261Internal Busf XX /2 9f XX /2 10f XX /2 11TCL27 TCL26 TCL253PM36SelectorTimer Clock Select Register 2 Port Mode Register 3BUZ/P36P36Output LatchCHAPTER 13 BUZZER OUTPUT CONTROL CIRCUIT13.1 Buzzer Output Control Circuit FunctionsThe buzzer output control circuit outputs 1.2 kHz, 2.4 kHz, 4.9 kHz, or 9.8 kHz frequency square waves. The buzzerfrequency selected with timer clock select register 2 (TCL2) is output from the BUZ/P36 pin.Follow the procedure below to output the buzzer frequency.(1) Select the buzzer output frequency with bits 5 to 7 (TCL25 to TCL27) of TCL2.(2) Set the P36 output latch to 0.(3) Set bit 6 (PM36) of port mode register 3 (PM3) to 0 (Set to output mode).Caution Buzzer output cannot be used when setting P36 output latch to 1.13.2 Buzzer Output Control Circuit ConfigurationThe buzzer output control circuit consists of the following hardware.Table 13-1. Buzzer Output Control Circuit ConfigurationItem ConfigurationTimer clock select register 2 (TCL2)Port mode register 3 (PM3)Figure 13-1. Buzzer Output Control Circuit Block DiagramControl register
